JP2538891B2 - Braking control system for unmanned vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a braking control device for an unmanned vehicle, and more particularly to a braking control device for an unmanned vehicle traveling by a motor.

(Prior Art) Conventionally, in an unmanned vehicle that is driven by a traveling motor,
For example, when a traveling obstacle is detected in front of the vehicle during traveling, the drive motor is stopped and a brake device such as a drum brake device is driven to suddenly stop the vehicle.

(Problems to be Solved by the Invention) However, when the unmanned vehicle has a heavy load, a high traveling speed, or a sudden stop at a high frequency, the friction portion of the brake device is greatly worn. It was necessary to replace parts such as brake shoes at high frequency.

An object of the present invention is to provide a braking control device for an unmanned vehicle that solves the above problems and can prolong the life of a brake device such as a drum brake device.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention has a stop command generation means, a traveling motor, a mechanical brake device, and a braking control means, and generates a stop command. The means is to issue a stop command when an obstacle is detected in the traveling direction of the unmanned vehicle, the traveling motor is operatively connected to the driving wheels of the unmanned vehicle to rotate the driving wheels, and the mechanical brake device is When the vehicle is driven, it mechanically participates in the drive wheel to brake the rotation of the drive wheel, and the braking control means electrically controls the rotation of the traveling motor so that the rotation of the drive wheel is braked during the operation. On the other hand, the driving of the mechanical brake device is controlled on and off, and the braking control means is configured to operate based on a stop command from a stop command generation means, and at the time of the operation, While the electric braking to the drive wheels based on the rotation control of the row motor is continuously performed until the rotation of the drive wheels stops, the first section, the last section, or the midway section of the duration of the electric braking. In part 1, the mechanical break device is driven only for a predetermined time, and the driving time of the mechanical brake device can be changed and adjusted.

(Operation) Therefore, in the present invention, when the unmanned vehicle is traveling, if there is an obstacle in the traveling direction of the unmanned vehicle, the stop instruction generating means issues a stop instruction. Then, the rotation of the traveling motor is electrically controlled so that the braking control means operates to brake the rotation of the drive wheels. Then, the electric braking to the drive wheels based on the rotation control of the traveling motor is continued until the rotation of the drive wheels is stopped. On the other hand, the mechanical brake device is partially driven for a predetermined time in a first section, a last section or an intermediate section of the duration of the electric braking. Therefore, mechanical braking plays an auxiliary role of electrical braking in braking the rotation of the drive wheels. or,
The braking distance of the unmanned vehicle is determined by the length of time that the mechanical brake device is driven.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, an unmanned vehicle 1 on which luggage can be placed is provided with driven wheels 2 on both front and rear sides thereof, and a drive wheel 3 is provided at a central portion thereof. As shown in FIG. 2, the drive wheel 3 has a rotating shaft 3a connected to a traveling motor 4. In this embodiment, a DC motor is used as the motor 4, and the drive motor 3 is driven to rotate the drive wheels 3 in the forward and reverse directions to move the vehicle forward and backward through a preset traveling path.

As shown in FIG. 3, the circuit configuration of the motor 4 includes a series circuit of a first transistor TR1 and a second transistor TR2 at both terminals of a DC power source Ev via a contactor 5, and a third circuit
The transistor TR3 and the series circuit of the fourth transistor TR4 are connected in parallel. The first transistor TR
The field winding 4a and the armature 4b of the traveling motor 4 are connected between 1 and the second transistor TR2 and between the third transistor TR3 and the fourth transistor TR4.

Then, when the contactor 5 is closed and a base current is supplied to the first and fourth transistors TR1 and TR4 to turn on both transistors TR1 and TR4, the current is applied to the traveling motor 4 in the direction indicated by the solid line in FIG. Flowing. Also, with the contactor 5 closed, the second and third transistors TR2, TR
When a base current is supplied to each of the transistors 3 and both transistors TR2 and TR3 are turned on, a current flows to the traveling motor 4 in the direction indicated by the broken line in FIG. 3 (opposite to the solid line). The rotation direction of the traveling motor 4 (the rotation direction of the drive wheels 3) is controlled by switching the direction in which the motor current flows.

The rotary shaft 3a of the drive wheel 3 shown in FIG. 2 is connected to a drum brake device 6 as a mechanical brake means, and the drive of the drum brake device 6 stops the rotation of the drive wheel 3. . That is, the drum brake device 6 presses the brake shoe against the drum to mechanically stop the rotation of the shaft 3a of the drive wheel 3 by the frictional force.

Further, radars 7 as stop command generating means are arranged on both front and rear sides (left and right sides in FIG. 1) of the unmanned vehicle 1 shown in FIG. This radar 7 detects an obstacle in front of the vehicle in the traveling direction (traveling direction), which is an obstacle to traveling, and outputs a stop signal when the obstacle is detected. Further, the unmanned vehicle 1 is equipped with a microcomputer 8 as a braking control means. When the microcomputer 8 inputs a stop signal from the radar 7, the contactor 5 and each transistor are based on the signal.
It controls TR1, TR2, TR3, TR4 and the drum brake device 6.

Next, the operation of the braking control device for the unmanned vehicle 1 configured as described above will be described with reference to FIG.

The microcomputer 8 outputs the contactor signal SG1 for closing the contactor 5 during normal traveling, and also the first and fourth transistors TR1, TR4 or the second and the fourth transistors TR1, TR4 for traveling the vehicle forward or backward. The transistors TR2 and TR3 of No. 3 are turned on to drive the traveling motor 4 in a predetermined rotation direction. And the traveling speed Va
When the radar 7 detects an obstacle that obstructs traveling in the traveling direction, the stop signal SG2 is output to the microcomputer 8.

When the microcomputer 8 receives the stop signal SG2, the traveling motor 4 moves in the opposite direction to the traveling direction of the vehicle at this time.
It outputs a motor current switching signal SG3 for rotating the. That is, in order to pass a current in the direction opposite to the direction of the current of the traveling motor 4 at that time, the first and fourth transistors are provided.
When TR1 and TR4 are on, the second and third transistors TR2 and TR3 are turned on, and when the second and third transistors TR2 and TR3 are on, the first and first transistors are turned on. Four
Turn on the transistors TR1 and TR4.

Then, the traveling motor 4 is subjected to anti-phase braking (plugging), torque is generated in the direction opposite to the traveling direction, and the traveling speed decreases.

Then, the microcomputer 8 outputs the brake signal SG4 to the drum brake device 6 when a predetermined time t1 has elapsed after inputting the stop signal SG2. By inputting this signal SG4, the brake shoe of the drum brake device 6 is expanded and the driving wheel 3 is mechanically braked by the frictional force with the inner surface of the drum to stop the unmanned vehicle 1. The fixed time t1 for driving the drum brake device 6 can be appropriately changed and set.

As described above, in this embodiment, when the stop signal SG2 is input, the vehicle can be stopped by driving the drum brake device 6 when the traveling speed is reduced by the antiphase braking and the predetermined time t1 has elapsed.

Therefore, in the conventional braking method, the driving of the traveling motor is stopped by the stop command such as the stop signal SG2 from the radar 7, and the brake device is also driven to stop the traveling. Although frequent replacement of the same parts is required, in the present embodiment, the drum brake device 6 only has to take part of braking for stopping. Therefore, the wear amount of the drum brake device 6 is small and the life of the brake device 6 can be extended even when the loaded weight is large, the traveling speed is high, or the sudden stop is frequently performed. Can be replaced less frequently.

Further, the braking distance can be selected by appropriately adjusting and setting the time t1 from the input of the stop signal SG2 to the driving of the drum brake device 6.

The present invention is not limited to the above embodiment, and when the stop signal SG2 is input as shown in FIG. 5, the drum brake device 6 is activated immediately after the motor current switching signal SG3 is output to apply the antiphase braking. The brake signal SG4 for driving is output. Then, the drive of the drum brake device 6 may be released when the predetermined time t2 has elapsed, and the drum brake device 6 may be stopped only by the antiphase braking.

In this case, the deceleration rate immediately before the stop is reduced, and the impact at the time of the stop can be mitigated.

Further, in each of the above-described embodiments, the drum brake device 6 is driven in the first or last section of the period in which the antiphase braking is applied. However, the drum brake device 6 is driven in the middle of the driving period.
May be driven.

Further, the brake means may use a disc brake device or the like other than the drum brake device 6, and the traveling motor may use various motors other than the DC motor. Further, as the braking method of the motor, various kinds of electric braking other than the antiphase braking may be adopted.

As described above in detail, according to the present invention, mechanical braking only plays an auxiliary role of electric braking in braking the rotation of the drive wheels, and the mechanical brake device is configured to rotate the drive wheels. Since it is only partially driven for a predetermined period of time during the braking period, the mechanical fatigue is reduced, the life of the device can be extended, the frequency of replacing the parts can be reduced, and the mechanical brake device can be used. This has an excellent effect that the braking distance of the unmanned vehicle can be appropriately set by changing and adjusting the driving time of the vehicle.

[Brief description of drawings]

FIG. 1 is a side view of an unmanned vehicle embodying the present invention, and FIG. 2 is a view showing driving wheels, a traveling motor, and a drum brake device,
FIG. 3 is a circuit diagram of the traveling motor, FIG. 4 is a diagram for explaining output timings of various signals and traveling speed, and FIG. 5 is a diagram showing another example. 1 is an unmanned vehicle, 3 is a drive wheel, 4 is a traveling motor, 6 is a drum brake device as a mechanical brake device, 7 is a radar as a stop command generating means, 8 is a microcomputer as a braking control means, and SG2 is a stop. It is a signal.

Claims (4)

(57) [Claims] 1. A stop command generating means (7), a traveling motor (4), a mechanical brake device (6), and a braking control means (8), wherein the stop command generating means (7) is unmanned. A stop command is issued when an obstacle is detected in the traveling direction of the vehicle (1), and the traveling motor (4) is operatively connected to the drive wheels (3) of the unmanned vehicle (1) to drive the drive wheels (3). The mechanical braking device (6) mechanically participates in the driving wheel (3) during driving to brake the rotation of the driving wheel (3), and the braking control means (8). ) Is a traveling motor (4) so that the rotation of the drive wheel (3) is braked during its operation.
Of the mechanical brake device (6) is controlled on and off while electrically controlling the rotation of the brake control device (6), and the braking control means (8) is operated based on the stop command from the stop command generation means (7). In this operation, electric braking of the drive wheels (3) based on the rotation control of the traveling motor (4) is continuously performed until the rotation of the drive wheels (3) is stopped. The mechanical braking device (6) is driven only for a predetermined time in a first section, a last section or an intermediate section of the duration of the dynamic braking, and the mechanical braking apparatus (6).
The braking control device for an unmanned vehicle is characterized in that the driving time of the vehicle can be changed and adjusted. 2. The braking control means (8) drives the mechanical braking device (6) for a fixed time (t2) in synchronization with the start of the electrical braking of the driving wheels (3), thereby performing the electrical braking. The braking control device for an unmanned vehicle according to claim 1, wherein the drive of the mechanical brake device (6) is released before the end of the. 3. The braking control means (8) drives the mechanical braking device (6) until the end of the electric braking after a lapse of a fixed time (t1) from the start of the electric braking on the drive wheel (3). The braking control device for an unmanned vehicle according to claim 1, which is a control device. 4. The braking control means (8) drives a mechanical braking device (6) after a certain time has elapsed from the start of the electric braking on the driving wheels (3), and the mechanical braking device (6) is driven before the end of the electric braking. The braking control device for an unmanned vehicle according to claim 1, wherein the drive of the mechanical braking device (6) is released.